On the fsx-id branch:  Remove the now unused FS API ID serialization and
parser support.  Minimize the FS API ID functions to a single constructor.

* subversion/libsvn_fs_x/temp_serializer.h
  (svn_fs_x__serialize_id,
   svn_fs_x__deserialize_id): Drop.

* subversion/libsvn_fs_x/temp_serializer.c
  (svn_fs_x__serialize_id,
   svn_fs_x__deserialize_id): Drop.

* subversion/libsvn_fs_x/id.h
  (svn_fs_x__id_node_id,
   svn_fs_x__id_noderev_id,
   svn_fs_x__id_is_txn,
   svn_fs_x__id_unparse,
   svn_fs_x__id_eq,
   svn_fs_x__id_copy,
   svn_fs_x__id_parse,
   svn_fs_x__id_serialize,
   svn_fs_x__id_deserialize): Drop.

* subversion/libsvn_fs_x/id.c
  (svn_fs_x__id_node_id,
   svn_fs_x__id_noderev_id,
   svn_fs_x__id_is_txn): Drop.
  (svn_fs_x__id_unparse): Rename to ...
  (id_unparse): ... this.
  (svn_fs_x__id_eq,
   id_check_related): Merge into ...
  (id_compare): ... this one.
  (id_vtable): Update function reference.
  (svn_fs_x__id_copy,
   id_parse,
   svn_fs_x__id_parse,
   svn_fs_x__id_serialize,
   svn_fs_x__id_deserialize): Drop.


git-svn-id: https://svn.apache.org/repos/asf/subversion/branches/fsx-id@1648097 13f79535-47bb-0310-9956-ffa450edef68